Development of the mobile Internet imposes higher requirements for quality of service and an Internet speed that can be provided by a cellular communications system. To further improve spectral efficiency and a user throughput of a system, a carrier aggregation technology is introduced to LTE-A (LTE-Advanced, LTE-Advanced): Carrier aggregation refers to that user equipment (User Equipment, UE) may simultaneously use multiple component carriers (CC, Component Carrier) to perform uplink and downlink communication, that is, the UE communicates with a network simultaneously in multiple cells, where each cell uses a carrier different from that used in another cell, so as to support high-speed data transmission. Of all these aggregated cells, one is a primary serving cell, and the other are secondary serving cells.
In an LTE system, carrier aggregation may be classified, according to locations of base stations, into intra-base station cell aggregation, inter-base station cell aggregation, and the like. The intra-base station cell aggregation refers to that serving cells aggregated for a UE all belong to a same base station. The inter-base station cell aggregation refers to that aggregated serving cells belong to different base stations, and better user experience can be brought in this aggregation manner.
In a current inter-base station carrier aggregation scenario, when data sent by a UE by using RLC of a secondary base station reaches a maximum quantity of retransmissions, in this case, if it is determined that a radio link failure occurs, and the UE initiates RRC (Radio Resource Control, radio resource control) connection re-establishment, a data packet loss will definitely be caused, thereby affecting user experience. Therefore, for an inter-base station cell aggregation manner, when an RLC entity of a secondary serving cell of the UE detects that a quantity of retransmissions reaches a maximum value, how to prevent the UE from initiating an RRC re-establishment process becomes a problem to be urgently resolved.